A possible plot could involve a spell gone wrong in the Harry Potter universe that opens a portal to the Hell Raiser world. As a result, some of the Hogwarts students get trapped in that terrifying realm. They then have to use their magic in new and creative ways to survive and find a way back home, all while being hunted by the hellish creatures. This could also lead to some of the Hell Raiser characters becoming interested in the power of magic and trying to take it for themselves.
Finding good 'Harry Potter x Hell Raiser' fanfiction can be a bit of a hunt. One approach could be to join relevant fan groups or forums. There, fans might share their favorite crossovers or even be working on their own. You could also check out Wattpad, though it might have a smaller selection compared to Archive of Our Own. Some fanfictions might explore how the characters from Harry Potter deal with the demons or otherworldly entities from Hell Raiser, while others could be more about the clash of magic systems from both universes.
One plot idea could be that Mavis gets lost in the wizarding world and Harry has to help her find her way back to her own world. Along the way, they face various challenges like dark wizards who want to capture Mavis for her unique magic. Another could be that there's a threat that endangers both their worlds, and they must combine their powers to stop it. Maybe there's a powerful dark force that is trying to merge the two worlds in a chaotic way, and Harry and Mavis are the only ones who can prevent it.
One possible plot could be that Sesshomaru somehow ends up in the wizarding world of Harry Potter. Maybe a magical portal or a powerful spell goes wrong. He then has to navigate this new world with its own set of rules and magic, and he might encounter Harry and his friends.
One possible plotline could be that Harry discovers his true heritage as a prince of hell and has to grapple with the dark powers that come with it while still trying to exist in the wizarding world. Another could be that he is in conflict with the forces of good in the wizarding world as they view his newfound identity as a threat. Maybe he has to form new alliances with darker creatures or beings from the underworld.
Well, perhaps Harry is magically transported to the realm of the dark elves. There, he has to learn their ways and magic in order to survive. He could befriend some of the dark elves who are outcasts in their own society, and together they try to change the perception of the dark elves in the wider magical world. It could also involve a battle where Harry uses his new - found knowledge of dark elf magic to defend both the wizarding world and the dark elf world from a common enemy.
A possible plot could be that Supergirl somehow ends up in the Harry Potter universe. She might use her powers to help Harry and his friends in their fight against Voldemort. And during their adventures together, she and Harry develop feelings for each other.
In a 'Harry Potter Immortal Gunslinger' fanfiction, there could be a plot where an entire group of immortal gunslingers are sent to the wizarding world to stop a great evil. They might be from a parallel universe where magic doesn't exist but advanced weaponry does. Their immortality gives them an edge as they battle against dark forces in the Harry Potter world. They could form alliances with the Order of the Phoenix or other good - minded wizards. Their gunslinger tactics and weapons could be a new and unexpected weapon against the dark arts. For instance, they might find that their bullets can disrupt certain dark magic spells, creating a whole new dynamic in the fight against evil in the wizarding world.
Perhaps Harry discovers he's a shapeshifter early on in his Hogwarts years. He might use this power to play pranks on the Slytherins by changing into a mouse and scaring them in the dungeons. But then, he realizes he has a greater responsibility when he sees the potential of using it against the Dark Arts. For example, he could shift into a large and powerful animal like a hippogriff to fight off Dementors.
One plot idea could be that there is a strange magical - scientific anomaly that threatens both the wizarding world and the Watchmen's world. Harry and Jon have to team up to figure out what's going on and stop it. Maybe it involves a dark wizard using some sort of Watchmen - inspired technology to create chaos.
One possible plot could be that the Joker somehow finds his way into the wizarding world. He starts causing chaos in Hogwarts, and Harry Potter has to figure out a way to stop him without using the Killing Curse. Maybe the Joker uses his mind - games on the students and teachers, creating a lot of confusion and mistrust within the school.